Wittgenstein's critique of private language in the Philosophical Investigations does not attempt to refute the possibility of a private sensation-language, let alone in any one argument, as has often been thought. Nor does it aim to establish that language is intrinsically social. Instead, PI ??243-315 presents a series of arguments, suggestions, questions, examples and thought-experiments whose purpose is to undermine the temptation to think of sensations and perceptual experiences as private objects occupying a private phenomenal space. These themes are clear developments of Wittgenstein's earlier critique of sense-datum theories (1929-1936) and his insight that naming is more complex than he had assumed in the Tractatus.